Friedreich's Ataxia Flashcards
What is ataxia?
Ataxia is a condition characterised by poor muscle control and uncoordinated movements.
There are many different types of Ataxia’s which affect different parts of the body, Friedrich’s Ataxia is one of these.
What is Freidrich’s ataxia
An autosomal, recessively inherited spinocerabellar ataxia, affect the spine and cerebellum
What causes Friedrich’s ataxia?
(5)
FA is a neurological disorder caused by a range of mutations on the frataxin gene of chromosome 9
The most common mutation is a GAA trinucleotide repeat but some cases are caused by deletions or point mutations
Most people have 40 GAA repeats, but anyone with 70+ repeats will suffer from FA
Even though 70 repeats is the cut-off for the disease most patients actually have 600-700 GAA repeats. The longer the repeat the earlier the onset of the disease and the worse the symptoms
Extensive DNA methylation can also be seen in patients just upstream of the GAA repeat, the extent of this methylation is inversely proportional to the severity of the condition
How prevalent is FA?
(4)
FA is a rare condition affecting 1 in every 50,000 people
There is an estimated 140 Irish people affected by the condition
It is more prevalent in some areas of the world such as Europe, Asia, the middle east and north africa
I in every 85 Europeans are heterozygous carriers of the condition
What are the effects of FA
(4)
The mutations of the frataxin gene cause a low level of frataxin protein production
Low frataxin causes a dis-regulation of iron transport in the mitochondria
This leads to iron overload and a build up of reactive oxygen species
This causes cell damage and a wide range of symptoms ensues
What are the signs and symptoms of FA
(9)
Lack of coordination
Tremors
Difficulty walking
Gait abnormalities
Deterioration of fine motor skills
Heart problems
Trouble swallowing and eating
Slurred speech
Eye movement abnormalities
